RICHMOND, Va. (Reuters) - Virginia Democrats pressured Lieutenant Governor Justin Fairfax to resign on Monday over accusations of sexual assault which he denies, but held off on pursuing impeachment, with the Republican speaker of the state House urging restraint.

Fairfax is one of three top Democrats in the state engulfed by scandal this month. Governor Ralph Northam and Attorney General Mark Herring have also faced criticism after admitting to having worn blackface in the 1980s.

Patrick Hope, a Democratic member of the state's House of Delegates, said he believed Fairfax should have resigned already after two women accused him of sexual assault but added he would not move immediately on his weekend call for impeachment proceedings.

The accusations of racist behavior or sexual assault targeting the three men have rattled party leadership in a swing state that likely will play a pivotal role in the 2020 U.S. presidential election.

In the unlikely event that all three men were to step down, the governorship would pass to the Republican speaker of the state house. That would be a stunning reversal in a state where Democrats have been gaining power in the last few election years.

Party leaders in the state and across the nation have called for Northam and Fairfax to resign over the accusations against them. They have been more forgiving toward Herring, largely because he came forward on his own to admit having performed in blackface at a 1980 college party, rather than waiting for someone else to accuse him.

Northam and Herring are white; Fairfax is black.

Hope, the white Democratic lawmaker who had called for Fairfax's impeachment, renewed his call for the lieutenant governor to resign while saying he was discussing whether impeachment was the best solution.

"Fairfax should have already resigned. It is atrocious that he will be presiding over the Senate of Virginia today with these allegations," Hope said in a statement. "The message being sent to victims of sexual assault is chilling."

He said he believed Fairfax's two accusers.

The scandals may cost the Democrats their chance to take over control of the legislature in November's elections, said Larry Sabato, the director of the University of Virginia's Center for Politics. The scandals have eroded voters' faith in the party to put forward good candidates, and any perceived racial disparities in consequences for the three officials may cause further harm, he said.

"You've got three of them in trouble, and then potentially the African-American goes and the two whites stay," he said in a telephone interview. "Now, there could be complete justification for that, but it looks terrible."

'VOLATILE SITUATION'

House Speaker Kirk Cox, the Republican who would become governor if all three Democrats stepped down, said it was too soon to say whether he would support the process of removing Fairfax from office.

"We are in a very volatile situation right now," he told reporters on Monday. "We need to be very careful with the high standards of impeachment."

Northam, meanwhile, insisted in an interview with CBS, first aired on Sunday, that he would not resign over the 1984 yearbook picture, which showed a person in blackface next to another wearing the robes and hood of the white supremacist Ku Klux Klan. Northam denied being in that picture but admitted to dressing in blackface for a social event that same year.

Blackface traces its history to 19th-century "minstrel" shows that mocked African-Americans and is seen as offensive by many Americans.

Northam said Fairfax would have to step aside if sexual assault allegations against him were found to be true.

Fairfax has said that encounters with both women were consensual. On Sunday, a spokeswoman for the lieutenant governor said he was "aggressively exploring options for a thorough, independent, and impartial investigation" of the allegations.